Bonding method and bonded structure

Abstract

A bonding method includes: preparing a first base material to have liquid repellency against a silicone material-containing liquid material; applying the liquid material to a surface of the first base material to form a liquid coating in a predetermined shape, and drying the liquid coating to obtain a bonding film with the predetermined shape; imparting energy to the bonding film to develop adhesion near a surface of the bonding film, and bonding the first base material to a second base material via the bonding film, and then separating the first and second base materials from each other to transfer the bonding film to the second base material; and imparting energy to the bonding film after the transfer to develop adhesion near a surface of the bonding film, and bonding the second base material to a third base material via the bonding film to obtain a bonded structure.

1 . A bonding method comprising:
 (1) preparing a first base material, a second base material and a third base material, the first base material having a liquid repellency-imparted surface that is repellent against a silicone material-containing liquid material;   (2) applying the silicone material-containing liquid material to the liquid repellency-imparted surface of the first base material to form a liquid coating in patterns of a predetermined shape, and drying the liquid coating to obtain a bonding film patterned into the predetermined shape;   (3) imparting energy to the bonding film to provide adhesion near a surface of the bonding film, and thereafter bonding the first base material and the second base material to each other via the bonding film, and then separating the first base material and the second base material from each other to transfer the bonding film from the first base material to the second base material; and   (4) imparting energy to the bonding film after the transfer to provide adhesion near another surface of the bonding film, and bonding the second base material and the third base material to each other via the bonding film to obtain a bonded structure of the second base material and the third base material.   
     
     
         2 . The bonding method according to  claim 1 , wherein, in step (2), the bonding film is formed over substantially an entire surface of the second base material to be bonded to the third base material. 
     
     
         3 . The bonding method according to  claim 1 , wherein, in step (2), the bonding film is formed over substantially an entire surface of the third base material to be bonded to the second base material. 
     
     
         4 . The bonding method according to  claim 1 , wherein, in step (2), the liquid coating is formed by supplying the liquid material in droplets using a droplet discharge method. 
     
     
         5 . The bonding method according to  claim 4 , wherein the droplet discharge method is an inkjet method by which the liquid material is discharged in droplets through a nozzle hole of an inkjet head using vibration of a piezoelectric element. 
     
     
         6 . The bonding method according to  claim 1 , wherein the predetermined shape corresponds in shape to a position where bonding by the bonding film is desired. 
     
     
         7 . The bonding method according to  claim 1 , wherein the silicone material-containing liquid material includes a silicone material having a main backbone of polydimethylsiloxane, and wherein the main backbone is branched. 
     
     
         8 . The bonding method according to  claim 7 , wherein at least one methyl group of the polydimethylsiloxane in the silicone material is substituted with a phenyl group. 
     
     
         9 . The bonding method according to  claim 1 , wherein the silicone material-containing liquid material includes a silicone material including a plurality of silanol groups. 
     
     
         10 . The bonding method according to  claim 1 , wherein the silicone material-containing liquid material includes a silicone material that is a polyester-modified silicone material obtained by a dehydrocondensation reaction with polyester resin. 
     
     
         11 . The bonding method according to  claim 10 , wherein the polyester resin is the product of esterification reaction between saturated polybasic acid and polyalcohol. 
     
     
         12 . The bonding method according to  claim 1 , wherein, in steps (3) and (4), energy is imparted to the bonding film by contacting a plasma with the bonding film. 
     
     
         13 . The bonding method according to  claim 12 , wherein the contacting is performed under atmospheric pressure. 
     
     
         14 . The bonding method according to  claim 12 , wherein the contacting is performed by supplying a plasma gas to the bonding film, wherein the plasma gas is produced by introducing a gas between opposing electrodes under applied voltage between the electrodes. 
     
     
         15 . The bonding method according to  claim 1 , wherein portions of the second base material and the third base material that are brought into contact with the bonding film are primarily formed of a silicon material, a metal material, or a glass material. 
     
     
         16 . The bonding method according to  claim 1 , wherein portions of the second base material and the third base material that will be brought into contact with the bonding film are subjected in advance to a surface treatment that improves adhesion for the bonding film. 
     
     
         17 . The bonding method according to  claim 16 , wherein the surface treatment is a plasma treatment or an ultraviolet ray irradiation treatment. 
     
     
         18 . The bonding method according to  claim 1 , further comprising subjecting the bonding film to a treatment that improves the bond strength between the second base material and the third base material, after the second base material and the third base material are bonded to each other. 
     
     
         19 . The bonding method according to  claim 18 , wherein the treatment to improve the bond strength is performed by at least one of heating the bonding film, and exerting a compression force to the bonding film. 
     
     
         20 . A bonding method comprising:
 (1) providing a first base with a surface that is repellent against a liquid containing a silicone material;   (2) forming a bonding film on the first base by:
 (a) applying the liquid to the surface of the first base to form a liquid coating in a predetermined shape on the surface; and 
 (b) drying the liquid coating to obtain a bonding film having the predetermined shape; 
   (3) transferring the bonding film from the first base to a second base by:
 (a) providing adhesion along a first surface of the bonding film by imparting energy to the bonding film; 
 (b) thereafter bonding the first surface of the bonding film to the second base; and 
 (c) thereafter separating the bonding film from the first base; and 
   (4) obtaining a bonded structure of the second base and a third base by:
 (a) after the transfer, providing adhesion along a second surface of the bonding film by imparting energy to the bonding film; and 
 (b) thereafter bonding the second surface of the bonding film to the third base.